Camera module

ABSTRACT

A camera module according to an embodiment of the present invention may include a first Printed Circuit Board (PCB) configured to have an image sensor mounted thereon; a housing unit disposed over the first PCB; a holder module spaced apart from a bottom surface within the housing unit at a specific interval and configured to have a first coil wound on its outer circumferential face and to include at least lens therein; a second PCB combined with the bottom surface of the holder module; a third PCB disposed over the holder module; and a plurality of wire springs each configured to have one end connected to the second PCB and the other end connected to the third PCB.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based on, and claims priority from, KoreanApplication Numbers 10-2011-0111005, filed on Oct. 28, 2011,10-2011-0112294, filed on Oct. 31, 2011, 10-2011-0112306 filed on Oct.31, 2011, 10-2011-0125616 filed on Nov. 29, 2011 and 10-2012-0013230filed on Feb. 9, 2012, the disclosure of which is incorporated byreference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a camera module.

2. Background of the Related Art

A camera module mounted on a small-sized electronic product may befrequently subject to a shock while in use. The camera module may beminutely shaken by a user's hand shaking during photographing. In viewof the above problems, there is recently being disclosed a camera modulehaving hand-shaking prevention means.

For example, Korean Registration Patent No. 10-0741823 (registered onJul. 16, 2007) discloses a method of installing a gyro sensor IC or anangular velocity sensor within a device on which a camera module ismounted, such as a mobile phone in order to correct a hand shakingphenomenon.

If an additional angular velocity sensor is provided as described above,an additional sensor must be provided in order to implement thehand-shaking prevention function. Accordingly, there are problems inthat manufacture costs are increased and an additional space where ahand-shaking prevention device will be constructed and installed must beprovided in addition to the camera module.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a camera modulehaving an optical image stabilizer function.

A camera module according to an embodiment of the present invention mayinclude a first Printed Circuit Board (PCB) configured to have an imagesensor mounted thereon; a housing unit disposed over the first PCB; aholder module spaced apart from a bottom surface within the housing unitat a specific interval and configured to have a first coil wound on itsouter circumferential face and to include at least lens therein; asecond PCB combined with the bottom surface of the holder module; athird PCB disposed over the holder module; and a plurality of wiresprings each configured to have one end connected to the second PCB andthe other end connected to the third PCB.

The buffer unit may be formed by curving the wire spring in zigzags ormay be formed by bending the wire spring in a coil spring form.

It is preferred that the housing unit include a first housing disposedon the upper side of the first PCB; a second housing disposed on theupper side of the first housing and configured to have the third PCBdisposed thereon; first and second permanent magnets interposed betweenthe first and the second housings; and yokes each disposed between thefirst and the second permanent magnets and configured to transfermagnetic force to the holder module.

The housing unit may include a first housing disposed on the upper sideof the first PCB; a second housing disposed on the upper side of thefirst housing and configured to have the third PCB disposed thereon;first and second permanent magnets placed on the insides of the firstand the second housings; and yokes each disposed between the first andthe second permanent magnets and configured to transfer magnetic forceto the holder module.

In accordance to an exemplary embodiment of the present invention, thecamera module may further include a shield can formed to have a throughhole at the connection unit of the third PCB and the wire spring and ata position corresponding to a lens module.

It is preferred that the holder module include an outer blade formed tohave the first coil wound on its outer circumferential face; a bobbinelastically supported by an elastic member on the upper side of theouter blade, disposed movably up and down within the outer blade, andconfigured to have a second coil wound on its outer circumferential faceand to have at least one lens installed therein; and upper and lowerelastic members disposed on the respective upper and lower sides of thebobbin and configured to elastically support the bobbin against theouter blade, wherein a space unit is formed at the center of the firstcoil so that magnetic force is applied toward the second coil.

Furthermore, the central part of the yoke toward the holder module maybe protruded.

It is preferred that the holder module include an outer blade formed tohave the first coil wound on its outer circumferential face; a bobbinelastically supported by an elastic member on the upper side of theouter blade, disposed movably up and down within the outer blade, andconfigured to have a second coil wound on its outer circumferential faceand to have at least one lens installed therein; and upper and lowerelastic members disposed on the respective upper and lower sides of thebobbin and configured to elastically support the bobbin against theouter blade.

The second PCB may be installed at the bottom surface of the outerblade.

It is preferred that the second PCB be fixed to the bottom surface ofthe outer blade by an adhesive member.

The wire springs may be made of metal material, and the wire springsconduct electricity to the second and the third PCBs.

Furthermore, it is preferred that the number of wire springs be at least6 so that a power source of two polarities for auto-focusing control anda power source of four polarities for optical image stabilizer aresupplied to the holder module through connection between the wiresprings and the second and the third PCBs.

Furthermore, it is preferred that four pairs of the wire springs havingan identical length be disposed at respective corners of the holdermodule.

Here, it is preferred that the second coil be electrically connected toa lower spring, and the lower spring be electrically connected to thewire spring in the second PCB.

Furthermore, the second coil may be directly connected to the second PCBso that the second coil conducts electricity to the second PCB.

Furthermore, a space unit may be formed at a center of the first coil sothat magnetic force is applied toward the second coil.

In accordance with the present invention, the wire springs can be firmlyconnected to the connection units of the PCBs because the buffer unitsfor absorbing load repeatedly applied to the wire springs are provided.

Furthermore, although excessive force is applied to the wire springs ina process of assembling the lens module, the buffer units can absorb theexcessive force. Accordingly, an assembly property can be improved, andthe loss of parts due to poor assembly can be minimized.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention can be more fullyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a schematic plan view of a camera module according to anembodiment of the present invention;

FIG. 2 is a sectional view of the camera module taken along line A-A ofFIG. 1 according to first and second embodiments of the presentinvention;

FIG. 3 is a side view of the camera module according to an embodiment ofthe present invention;

FIG. 4 is a side view of the camera module from which a shield can ofFIG. 3 has been removed;

FIG. 5 is an enlarged view of a part B of FIG. 2 according to the firstembodiment of the present invention;

FIG. 6 is an enlarged view of the part B of FIG. 2 according to thesecond embodiment of the present invention;

FIG. 7 is a schematic sectional view of the camera module taken alongline A-A of FIG. 1 according to a third embodiment of the presentinvention;

FIG. 8 is an enlarged view of a part C of FIG. 7 according to the thirdembodiment of the present invention;

FIG. 9 is a schematic sectional view of the camera module taken alongline A-A of FIG. 1 according to a fourth embodiment of the presentinvention;

FIG. 10 is an enlarged view of a part D of FIG. 9 according to thefourth embodiment of the present invention;

FIG. 11 is a schematic sectional view of the camera module taken alongline A-A of FIG. 1 according to a fifth embodiment of the presentinvention;

FIG. 12 is a schematic sectional view of the camera module taken alongline A-A of FIG. 1 according to a sixth embodiment of the presentinvention;

FIG. 13 is a schematic sectional view of the camera module taken alongline A-A of FIG. 1 according to a seventh embodiment of the presentinvention;

FIGS. 14 and 15 are enlarged views of a part E of FIG. 13 and arediagrams schematically illustrating the operation state of an impactabsorption unit according to the seventh embodiment of the presentinvention;

FIG. 16 is a block diagram of a camera module according to an embodimentof the present invention;

FIG. 17 is a schematic sectional view showing an example of a cameramodule according to an embodiment of the present invention; and

FIG. 18 is a schematic sectional view showing another example of acamera module according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, some exemplary embodiments of the present invention aredescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic plan view of a camera module according to anembodiment of the present invention, FIG. 2 is a sectional view of thecamera module taken along line A-A of FIG. 1 according to first andsecond embodiments of the present invention, FIG. 3 is a side view ofthe camera module according to an embodiment of the present invention;

FIG. 4 is a side view of the camera module from which a shield can ofFIG. 3 has been removed, FIG. 5 is an enlarged view of a part B of FIG.2 according to a first embodiment of the present invention, and FIG. 6is an enlarged view of a part B of FIG. 2 according to a secondembodiment of the present invention.

As shown in FIG. 1 showing the schematic plan view and FIG. 2 showingthe schematic side view of line A-A in FIG. 1, the camera moduleaccording to the present invention includes a first Printed CircuitBoard (hereinafter referred to as a PCB) 10, a housing unit 20, a holdermodule 30, a second PCB 40, a third PCB 50, wire springs 60, and bufferunits 100.

It is preferred that an image sensor 11 be mounted approximately on thecentral part of the first PCB 10. Elements for driving the image sensor11 may be disposed in the first PCB 10 or a plurality of terminal unitsfor supplying power and outputting information from the image sensor 11may be provided in the first PCB 10.

The housing unit 20 is disposed over the first PCB 10, and it forms theframework of the camera module. In accordance with an exemplaryembodiment of the present invention, the housing unit 20 includes afirst housing 21, a second housing 22, pairs of first and secondpermanent magnets 23 and 24, and a plurality of yokes 25.

The first housing 21 is a base and is disposed on the top of the firstPCB 10 and spaced apart from the image sensor 11 at a specific interval.A filter member for filtering an image phase incident on the imagesensor 11 may be further included in the first housing 21 as occasiondemands.

The second housing 22 is disposed on the top of the first housing 21 andis configured to cover the first housing 21. An opening is formedapproximately at the center of the second housing 22 so that an imagecan be transferred to the image sensor 11. The third PCB 50 is adheredand fixed to the upper lateral face of the second housing 22 using afixing member to be described later, such as a double-sided tape or anadhesive, but not limited thereto. In some embodiments, however, anadditional third housing, such as a casing or a shield can, may beprovided, and the third PCB 50 may be fixed to the inside of theadditional third housing the fixing member according to a productdesign. If the third housing is provided, the third housing may pressand support the third PCB 50 without an additional fixing member.

The first and the second permanent magnets 23 and 24 are interposedbetween the first and the second housings 21 and 22 and are configuredto apply magnetic force to the holder module 30. It is preferred thatthe first and the second permanent magnets 23 and 24 have the same size.Furthermore, the first and the second permanent magnets 23 and 24 andthe yoke 25 may be disposed on the inside of the first and the secondhousing 21 and 22, if possible, within a design tolerance limit.

Meanwhile, if the size of the first and the second permanent magnets 23and 24 is increased, Optical Image Stabilization (OIS) driving isincreased even by low current. If the first and the second permanentmagnets 23 and 24 are configured to have a specific size, OIS driving isincreased as current flowing into first and the second coils 31 a to 31d and 32 a disposed at positions corresponding to the first and thesecond permanent magnets 23 and 24 is increased. Accordingly, OISdriving becomes better according to an increase of the first and thesecond permanent magnets 23 and 24, but it is preferred that the firstand the second permanent magnets 23 and 24 have an optimized size withina design tolerance limit.

Each of the yokes 25 is interposed between each of the pairs of firstand the second permanent magnets 23 and 24. Furthermore, the centralportion of the yoke 25 is configured to have a protruded shape so thatthe pair of first and second permanent magnets 23 and 24 may applymagnetic force to the internal space of the holder module 30. It ispreferred that the yoke 25 be configured to the same width as the pairof first and second permanent magnets 23 and 24, the center of the yoke25 be protruded in a specific size, and the pair of first and secondpermanent magnets 23 and 24 and the yoke 25 have an approximately ‘T’shape.

The holder module 30 is spaced apart from the bottom surface of theinside of the housing unit 20 and is formed of an outer blade 31 and abobbin 32. The holder module 30 may perform a pendulum movement in thefront/rear, left/right, and diagonal directions with it dangled from thewire springs 60.

Spring members 35 and 36 are provided in the upper and lower parts ofthe outer blade 31, respectively. The outer blade 31 is elasticallysupported by the spring member 35 so that the bobbin 32 is moved up anddown.

As shown in FIG. 1, a total of four first coils 31 a to 31 d are woundon the four outer faces of the outer blade 31, respectively, and thecentral part of each of the four outer faces of the outer blade 31 onwhich the first coils 31 a to 31 d are wound is perforated without acoil. Each of the yokes 25 is disposed at a position corresponding tothe perforated space unit, and thus the yoke 25 may be partiallyinserted into the space unit.

The second PCB 40 may be fixed to the bottom of the outer blade 31 usinga fixing member 33, such as a double-sided tape or an adhesive. Theouter blade 31 is dangled from the plurality of wire springs 60 so thatthe outer blade 31 can move in the front/rear and left/right directionsor in a diagonal line according to an interaction between the magneticforce of the first and the second permanent magnets 22 and 23 and thefirst coils 31 a, as indicated by an arrow of FIG. 2. Furthermore, theouter blade 31 is spaced apart from the bottom surface of the firsthousing 21 at a specific interval.

Furthermore, a plurality of spring through holes 37 may be provided inthe outer blade 31 so that the wire springs 60 are connected to thesecond PCB 40 through the spring through holes 37.

The bobbin 32 is disposed within the outer blade 31 so that it ismovable up and down. At least one lens 34 is installed within the bobbin32. The second coil 32 a is wound on the outer circumferential face ofthe bobbin 32. The second coil 32 a performs an operation of raising upand lowering the bobbin 32 through an interaction with the magneticforce applied through the perforated spaces without the first coils 31 ato 31 d of the outer blade 31 through the yokes 25. As the size of theyoke 25 increases, AF driving may become better, but may be changedaccording to an optimal design value. It is possible to automaticallycontrol the focus of an image transferred to the image sensor 11 throughthe raising action of the bobbin 32.

The second PCB 40 is disposed at the bottom surface of the outer blade31 as described above and is connected to the wire springs 60 so that itcan supply a power source to the first and the second coils 31 a to 31 dand 32 a. This connection method may include any method if soldering orother conductive substances may be used. That is, the connection unitsw′ of the second PCB 40 are connected to the first coils 31 a to 31 d,respectively, and the second coil 32 a, as shown in, FIG. 2. Thus, apower source supplied through the wire springs 60 is transferred to thefirst and the second coils 31 a to 31 d and 32 a, thus formingelectromagnetic force.

Here, the second coil 32 a may be directly connected to the second PCB40, or the second coil 32 a may be connected to the lower spring 36 andthe lower spring 36 may be then connected to the second PCB 40 as shownin FIG. 2.

The third PCB 50 is fixed to the top of the second housing 22 using thefixing member, such as a double-sided tape or an adhesive member, asdescribed above. A power source transferred through the terminal unit 52of the third PCB 50 connected to the first PCB 10 is transferred to thesecond PCB 40 through the wire springs 60 connected to the second PCB40. This connection method may include any method if soldering or otherconductive substances may be used.

The third PCB 50 may be provided to cover the walls of the first and thesecond housings 21 and 22 on one side, as shown in FIGS. 3 and 4. Here,a window 55 may be formed in a surface of the third PCB 50 where thethird PCB 50 faces the first and the second permanent magnets 23 and 24and the yoke 25 in order to avoid interference therebetween.

The window 55 functions to prevent the third PCB 50 from beinginfluenced by coupling portions because the first and the secondpermanent magnets 23 and 24 and the yoke 25 are directly adhered to ashield can 70 (described later) by using the fixing means, such asepoxy.

Meanwhile, a flexible PCB (FPCB), a PCB, or a rigid FPCB integrationtype (R-FPCB) may be used as each of the second PCB 40 and the third PCB50, but not limited thereto. Any board may be used as the second PCB 40and the third PCB 50 if the board enables electrical connection.

Each of the wire springs 60 has both ends connected to the second andthe third PCBs 40 and 50. Here, one end of the wire spring 60 isconnected to a pad 51 formed in the third PCB 50 as shown in FIG. 5. Athrough hole 53 through which the wire spring 60 passes is formed at thecenter of the pad 51. In this case, a connection method may include anymethod if soldering or other conductive substances may be used.Meanwhile, a Solder Register (SR) is provided around the pad 51, thusprotecting a surface of the third PCB 50. The area of the pad 51 may beconnected by opening the SR so that the area is conductive.

The wire spring 60 connected at the pad 51 as described above suppliesthe power source from the terminal unit 52 to the second PCB 40, so thatthe first and the second coils 31 a to 31 d and 32 a may interact withthe first and the second permanent magnets 23 and 24.

Furthermore, the other end of the wire spring 60 is connected to thesecond PCB 40, provided at the bottom surface of the outer blade 31,through the spring through hole 37 formed in the outer blade 31, asshown in FIG. 2. As in the third PCB 50, the other end of the wirespring 60 is connected at a pad (not shown) formed in the second PCB 40,although (not shown). A through hole (not shown) through which the wirespring 60 passes is formed at the center of the pad (not shown). In thiscase, a connection method may include any method if soldering or otherconductive substances may be used. In this construction, the outer blade31 may be dangled from the wire springs 60 and may be spaced apart fromthe bottom surface of the first housing 21. In this case, the outerblade 31 performs a pendulum movement according to an interactionbetween the first coils 31 a to 31 d and the first and the secondpermanent magnets 23 and 24. Accordingly, the vibration of the outerblade 31 due to hand shaking can be corrected by the interaction betweenthe first coils 31 a to 31 d and the first and the second permanentmagnets 23 and 24. To this end, it is preferred that the wire spring 60be made of metal material that has elasticity enough to withstand ashock and conductivity.

Meanwhile, as the thickness of the wire spring 60 is reduced, opticalimage stabilizer motility becomes better even at a low current, but maybe changed according to an optimal design value. It is preferred thatthe thickness of the wire spring 60 be several μm to several hundreds ofμm, more preferably, 1 to 100 μm.

Furthermore, it is preferred that the number of wire springs 60 be atleast six. It is necessary to supply a power source of two polaritiesfor auto-focusing control and a power source of four polarities foroptical image stabilizer to the holder module 30 through connectionbetween the wire springs 60 and the second and the third PCBs 40 and 50.

In accordance with an exemplary embodiment of the present invention, itis preferred that four pairs of the wire springs 60 having the samelength are disposed at the respective corners of the holder module 30 inorder to keep the balance, as shown in FIGS. 1 and 2.

Meanwhile, if a third housing, such as the shield can 70, is furtherincluded as shown in FIG. 2, the windows 55 for covering the walls ofthe first and the second housings 21 and 22 are formed in the third PCB50 in order to avoid the coupling parts because the first and the secondpermanent magnets 23 and 24 and the yokes 25 are fixed to the shield can70 using epoxy, as described above.

If the shield can 70 is omitted, the first and the second permanentmagnets 23 and 24 and the yokes 25 may be attached and fixed within thethird PCB 50. In some embodiments, the windows 55 may be formed in thethird PCB 50 as described above, and the first and the second permanentmagnets 23 and 24 and the yokes 25 may be inserted into the windows 55.Reinforcement may be additionally performed outside the third PCB 50using a shielding tape.

It is preferred that the buffer units 100 be integrally formed with somesections of each of the wire springs 60. The buffer unit 100 may beformed by bending the wire spring 60 in zigzags as shown in FIG. 5 ormay be formed by bending the wire spring 60 in the form of a coil springas shown in FIG. 6.

Here, the shape of the second housing 22 may be designed so that thebuffer unit 100 is placed at a position where the wire spring 60 doesnot interfere with the second housing 22.

The buffer unit 100 has a downward tapered structure. It is preferredthat the buffer unit 100 have a conical funnel shape that is downwardlytapered, as shown in FIGS. 5 and 6. The support hole 122 is formed inthe same axis as the through hole 53. It is preferred that the supporthole 122 have a diameter equal to or greater than the through hole 53.

The through hole 53 may have a diameter slightly greater than the wirespring 60. The diameter of the through hole 53 may be designed such thata connection substance, such as soldering, or another conductivesubstance, flows out through the through hole 53 when the wire spring 60is connected at the pad 51 formed in the third PCB 50 and then theconnection substance is connected to the wire spring 60 on both the topand bottom surfaces of the third PCB 50.

The diameter of the support hole 122 may be slightly greater than thediameter of the wire spring 60. Alternatively, the diameter of thesupport hole 122 may be equal to or greater than the diameter of thethrough hole 53. That is, the diameter of the support hole 122 may bedesigned in order to prevent interference occurring because the wirespring 60 comes in contact with the second holder 22 near the supporthole 2.

The buffer unit 100 constructed as described above functions to absorbload applied to the wire spring 60. Accordingly, load applied to the pad51 provided in the third PCB 50 can be reduced, thereby being capable ofreducing load directly applied to a connection unit w that fixes thewire spring 60.

Meanwhile, in a common assembly process, after the bobbin 32 and theouter blade 31 are combined, the second housing 22, the second and thethird PCBs 40 and 50, and the wire springs 60 are coupled, the bobbin 32including a lens barrel is combined, the first housing 21 is connected,and the first housing 21 is then mounted on the first PCB 10 by using ajig. Alternatively, the permanent magnets and the yokes may be combinedbefore the first housing 21 is connected. The sequence of the aboveassembly may be changed as occasion demands. In other words, theassembly may be directly performed in equipment without a jig. In thisprocess, although force for inserting and combining the bobbin 32including the lens barrel is excessively great and the connection unitsw are adversely affected by the excessive force, the buffer units 100may absorb the excessive force.

In other words, the buffer unit 100 absorbs load, generated in the wirespring 60 around the connection unit w of the wire spring 60 and thethird PCB 50 and then pulled in the direction of gravity, and loadgenerated when the wire spring 60 is shaken left and right in the formof transformation energy, as shown in FIGS. 2, 5, and 6.

It is thus possible to prevent a problem that a connection work must beperformed again or a problem that a damaged product may not be used dueto the connection unit w broken during an assembly process. Accordingly,a more reliable camera module may be fabricated.

In accordance with a second exemplary embodiment of the presentinvention, the camera unit may further include a buffer member 1100instead of the buffer units 100 used in the first and secondembodiments, as shown in FIGS. 7 and 8.

The buffer member 1100 is interposed between the second housing 22 andthe third PCB 50 as shown in FIG. 7. The buffer member 1100 functions todistribute load applied to the connection units w by absorbing forcegenerated in the pads 51 or the wire springs 60 provided in the thirdPCB 50 in order to couple the wire springs 60 and the third PCB 50.

The through hole 53 may have a diameter slightly greater than the wirespring 60. The diameter of the through hole 53 may be designed such thata connection substance, such as soldering, or another conductivesubstance, flows out through the through hole 53 when the wire spring 60is connected at the pad 51 formed in the third PCB 50 and then theconnection substance is connected to the wire spring 60 on both the topand bottom surfaces of the third PCB 50.

The diameter of the support hole 122 may be slightly greater than thediameter of the wire spring 60. That is, the diameter of the supporthole 122 may be designed to be greater than the diameter of the throughhole 53 in order to prevent interference occurring because the wirespring 60 comes in contact with the second holder 22 near the supporthole 2.

In accordance with a third exemplary embodiment of the presentinvention, it is preferred that the buffer member 1100 be disposed onthe entire surface that faces the third PCB 50 over the second housing22. Although not shown, the buffer members 1100 may be disposed onlynear the connection units w.

The buffer member 1100 may be formed of an impact-resistant member, suchas microcellular polyurethane foam. For example, PORON may be used asthe microcellular polyurethane foam, but not limited thereto. Anymaterial that may be elastically deformed by external force may be usedas the buffer member 1100.

The buffer member 1100 may be spaced apart from the ends of the pad 51and the through hole 53 at a specific interval in order to prevent thethird PCB 50 from being torn. As shown in FIG. 5, the buffer member 1100may be disposed between the end of the through hole 53 and the end ofthe pad 51 and configured to fix the third PCB 50 and the second housing22 and to reduce load directly added to the connection unit w that fixesthe wire spring 60.

Furthermore, the buffer member 1100 may be disposed between the thirdPCB 50 and the second housing 22 at the end of the support hole 122 orat a position (not shown) spaced apart from the end of the support hole122 at a specific interval in order to absorb shock.

That is, as shown in FIGS. 7 and 8, the buffer member 1100 is disposedso that it comes into a surface contact with the pad 51. Accordingly,load generated in the wire spring 60 and then pulled in the direction ofgravity or load generated when the wire spring 60 is shaken left andright is primarily applied to the pad 51. The force applied to the pad51 is transferred to the buffer member 1100. Thus, the buffer member1100 absorbs the load energy in the form of transformation energy byelastically transforming the force.

It is thus possible to prevent a problem that a connection work must beperformed again or a problem that a damaged product may not be used dueto the connection unit w broken during an assembly process.

In accordance with fourth to sixth embodiments of the present invention,buffer units 2100 may be formed in respective wire springs 60.

It is preferred that the buffer units 2100 be integrally formed withsome region of each of the wire springs 60. In accordance with a fourthexemplary embodiment of the present invention, it is preferred that thebuffer units 2100 be formed near the connection unit w of the wirespring 60 and the third PCB 50 and a connection unit w′ of the wiresprings 60 and the second PCB 40, as shown in FIGS. 9 and 10.

It is preferred that each of the buffer units 2100 include first andsecond curved parts 2110 and 2120 at a position not interfering with thesecond housing 22 of the wire spring 60, but not limited thereto. Forexample, the buffer unit 2100 may be curved twice or more at need inorder to absorb load applied to the wire spring 60 at the curved points.

That is, as shown in FIG. 3, the first and the second curved parts 2110and 2120 may become the center of the moment of the curved wire spring60 depending on load applied to the wire spring 60 so that they aredeformed in a straight-line direction to the curved wire spring 60.Accordingly, deformation around each of the first and the second curvedparts 2110 and 2120 functions to absorb load applied to the wire spring60. Consequently, load applied to the pad 51 provided in the third PCB50 can be reduced, and thus load directly added to the connection unit wthat fixes the wire spring 60 can be reduced.

In accordance with a fifth exemplary embodiment of the presentinvention, the buffer unit 2100 may be formed near the connection unit wof the wire spring 60 and the third PCB 50, as shown in FIG. 11. Thatis, the connection unit w of the wire spring 60 and the third PCB 50corresponds to a position on which the load of the wire spring 60hanging the holder module 30 is concentrated. Thus, relatively greatforce is applied to the connection unit w of the wire spring 60 and thethird PCB 50 than to the connection unit w′ connected to the second PCB40 installed at the bottom surface of the outer blade 31. For thisreason, the buffer unit 2100 may be provided at a position close to theconnection unit w of the wire spring 60 and the third PCB 50.

In accordance with a sixth exemplary embodiment of the presentinvention, the buffer unit 2100 may be formed at a position near theconnection unit w′ of the wire spring 60 and the second PCB 40, as shownin FIG. 12. As described above in connection with the second embodiment,a position on which load is concentrated is the connection unit w of thewire spring 60 and the third PCB 50. Although the buffer unit 2100 isinstalled at a position near the connection unit w′ of the wire spring60 and the second PCB 40 on the extension line of load, however, load isabsorbed at the position as in the first and the second embodiments. Asa result, load applied to the connection unit w of the wire spring 60and the third PCB 50 can be reduced.

In accordance with this construction, the buffer unit 2100 absorbs load,generated the wire spring 60 near the connection unit w of the wirespring 60 and the third PCB 50 and then pulled in the direction ofgravity, or load, generated when the wire spring 60 is shaken left andright, in the form of transformation energy as shown in FIGS. 9 to 12.

It is thus possible to prevent a problem that a connection work must beperformed again or a part may not be used again due to the connectionunits w and w′ broken during an assembly process. Accordingly, a morereliable camera module may be fabricated.

In accordance with a seventh exemplary embodiment of the presentinvention, an impact absorption unit 3100 instead of the buffer units100 and 2100 may be formed in the second housing 22.

That is, the impact absorption unit 3100 may be formed in the sidewallof the second housing 22 to a specific depth and may be provided in theform of one or more grooves as shown in FIGS. 13 to 15. The impactabsorption unit 3100 formed to have the groove form may have a depthsmaller than the thickness of the second housing 22.

It is preferred that the impact absorption units 3100 be formed in theentire sidewall of the second housing 22 to a specific depth in the formof one or more grooves. Here, the grooves have the same depth, and theymay be spaced apart from one another at specific intervals. Furthermore,the impact absorption units 3100 may be formed in the inside and outsidefaces of the second housing 22 in such a way as to cross each other asshown in FIGS. 13 to 15.

When the impact absorption units 3100 are formed as described above, thesidewall of the second housing 22 has a zigzag section. Thus, both thewall faces of the impact absorption unit 3100 formed to have a grooveform become close to each other as shown in FIG. 6 when an externalimpact is applied to the second housing 22. Accordingly, the secondhousing 22 can be elastically deformed and thus external impact energymay be switched to the displacement energy of the second housing 22.Since the impact absorption units 3100 can absorb the external impactthrough the elastic deformation of the second housing 22, load due tothe movement of the holder module 30 transferred to the connection unitsw of the wire springs 60 and the third PCB 50 can be reduced, therebybeing capable of minimizing damage to the connection units w.

Likewise, the same effects may be expected if material used to form thesidewall of the second housing 22 is replaced with only elasticallydeformable material instead of the impact absorption units 3100. If toosoft material, such as silicon or rubber, is used, however, the movementof the holder module 30 may be influenced. For this reason, theelastically deformable material needs to maintain strength having aspecific level or higher.

Meanwhile, the camera module of the present invention may furtherinclude a shield can 70 configured to have through holes at respectivepositions corresponding to the lens module 30 around the connectionunits w of the third PCB 50 and the wire springs 60 and to surround thehousing units 21 and 22. In this case, the third PCB 50 may be attachedto the inner circumferential face of the shield can 70 as describedabove. Meanwhile, the shield can 70 is not indispensably necessary andmay be omitted depending on the constructions of the housing units 21and 22.

Meanwhile, as shown in FIG. 2, the camera module of the presentinvention may further include a hook unit 80 provided at each of thefour faces or at one or more faces in order to fix the shield can 70 tothe first housing 21. The position of the hook unit 80 may be within arange in which the center or corner design is allowed. The number ofhook units 80 may be one or more.

The hook unit 80 may include a hook 81 protruded into the first housing21 and a hook hole 82 formed to penetrate the shield can 70 facing thehook 81, and an opposite construction is also possible at need.

Meanwhile, the camera module of the present invention may control anOptical Image Stabilization (OIS) driver in order to reduce an impactagainst the internal structures of the camera module resulting from adrop.

FIG. 16 is a block diagram of a camera module according to an embodimentof the present invention.

The camera module according to the embodiment of the present inventionincludes a position detection portion 4100 for detecting the position ofthe camera module, a controller 4110 for generating a control signalwhen the position of the camera module detected by the positiondetection portion 4100 corresponds to a condition that the camera moduledrops, and an OIS driver 4120 for reducing an impact applied to theinternal structures of the camera module in response to the controlsignal of the controller 4110.

That is, when the camera module drops, the position detection portion4100 detects the position of the camera module. The controller 4110determines whether data regarding the detected position of the cameramodule satisfies the condition that the camera module drops.

If, as a result of the determination, the data regarding the detectedposition of the camera module satisfies the condition that the cameramodule drops, the controller 4110 outputs the control signal to the OISdriver 4120. The OIS driver 4120 reduces an impact applied to theinternal structures of the camera module resulting from the drop.

The position detection portion 4100 may include at least one of a gyrosensor, an acceleration sensor, and an angular velocity sensor.

FIG. 17 is a schematic sectional view showing an example of a cameramodule according to an embodiment of the present invention.

The camera module 4200 according to the embodiment of the presentinvention may be the OIS driver driven according to a lens barrel shiftmethod or a camera module tilt method.

As shown in FIG. 17, the camera module 4200 using the lens barrel shiftmethod includes a lens barrel 4250 including at least one sheet of alens and a casing 4210 having the lens barrel 4250 embedded therein.

Furthermore, the OIS driver of the camera module using the lens barrelshift method moves the lens barrel 4250 and further includes a coil 4220installed in the lens barrel 4250 and magnets 4230 disposed within thecasing 4210.

The positions where the coil 4220 and the magnet 4230 are installed atthe lens barrel 4250 and the casing 4210, respectively, may be reversed.

Furthermore, the lens barrel 4250 may be suspended from the casing 2410through wire springs 4260.

The wire springs 4260 provide flexibility for the left and rightoperations of the lens barrel 4250. The wire springs 4260 are connectedto the coil 4220 and configured to supply current to the coil 4220.

That is, when current is supplied to the coil 4220 through the wiresprings 4260, magnetic force is generated between the coil 4220 and themagnets 4230, thus limiting the x-axis and y-axis movements of the lensbarrel 4250. Accordingly, although great stress is applied to the lensbarrel 4250, a buffering action for preventing the lens barrel 4250 frombeing broken is possible.

FIG. 18 is a schematic sectional view showing another example of acamera module according to an embodiment of the present invention.

The camera module of FIG. 18 includes the above-described OIS driverdriven according to the camera module tilt method. The camera module4300 using the camera module tilt method includes a camera unit 4350configured to capture an optical image of a subject and a casing 4330configured to have the camera unit 4350 embedded therein.

The OIS driver may include magnets 4320 installed in the camera unit4350 and coils 4310 installed within the casing 4330.

The positions where the coils 4310 and the magnets 4320 of the OISdriver are installed at the camera unit 4350 and the casing 4330,respectively, may be reversed.

Furthermore, the camera unit 4350 may be suspended from the casing 4330through wire springs 4360, and current may be supplied to the coils 4310through the wire springs 4360.

In the camera module 4300 using the camera module tilt method, thex-axis and y-axis movements of the camera unit 4350 are limited bymagnetic force generated between the coils 4310 and the magnets 4320.Accordingly, the internal structures of the camera unit 4350 can beprevented from being broken.

In order to prevent the center of the camera unit 4350 from moving, agroove 4351 may be formed at the center of the bottom of the camera unit4350. A pivot 4370 inserted into the groove 4351 may be formed in thecasing 4330.

The groove 4351 and the pivot 4370 functions to balance the camera unit4350 before and after Optical Image Stabilization (OIS) driving.

Furthermore, the groove 4351 may be formed at an additional support unitplaced under the camera unit 4350.

Furthermore, the wire springs 4360 may function to support the cameraunit 4350 to the pivot 4370.

Furthermore, when the electromagnetic action of the OIS driverdisappears, the wire springs 4360 function to return the camera unit4350 to an original position or an additional elastic unit forperforming the restoration function may be further included in thecamera unit 4350.

That is, the elastic unit may be connected to the lens barrel 4250 ofFIG. 17 or the camera unit 4350 of FIG. 18 and the casing 4210 or 4330.The elastic unit may be formed of a member, such as a wire spring or asheet spring having excellent force of restitution when theelectromagnetic action does not exist because the supply of a powersource to the coils of the OIS driver is stopped, but not limitedthereto.

As described above, the camera module according to the present inventiondetects a drop of the camera module based on position data detected bythe position detection portion and drives the OIS driver. Accordingly,an impact against the internal structures of the camera module resultingfrom the drop can be reduced.

The embodiments of the present invention described above and shown inthe drawings should not be construed as limiting the technical spirit ofthe present invention. The scope of the present invention is restrictedby only the claims, and a person having ordinary skill in the art towhich the present invention pertains may improve and modify thetechnical spirit of the present invention in various forms. Accordingly,the modifications and modifications will fall within the scope of thepresent invention as long as they are evident to those skilled in theart.

What is claimed is:
 1. A camera module, comprising: a first PrintedCircuit Board (PCB) configured to have an image sensor mounted thereon;a housing unit disposed over the first PCB; a holder module spaced apartfrom a bottom surface within the housing unit at a specific interval andconfigured to have a first coil wound on its outer circumferential faceand to include at least one lens therein; a second PCB combined with thebottom surface of the holder module; a third PCB disposed over theholder module; a plurality of wire springs each configured to have oneend connected to the second PCB and the other end connected to the thirdPCB; and buffer units each integrally formed with a wire spring at aposition where the wire spring is connected to the third PCB, whereinthe buffer units are formed by curving the wire springs in zigzags. 2.The camera module as claimed in claim 1, wherein the housing unitcomprises: a first housing disposed on an upper side of the first PCB; asecond housing disposed on an upper side of the first housing andconfigured to have the third PCB disposed thereon; first and secondpermanent magnets interposed between the first and the second housings;and yokes each disposed between the first and the second permanentmagnets and configured to transfer magnetic force to the holder module.3. The camera module as claimed in claim 1, wherein the housing unitcomprises: a first housing disposed on an upper side of the first PCB; asecond housing disposed on an upper side of the first housing andconfigured to have the third PCB disposed thereon; first and secondpermanent magnets placed on insides of the first and the secondhousings; and yokes each disposed between the first and the secondpermanent magnets and configured to transfer magnetic force to theholder module.
 4. The camera module as claimed in claim 1, furthercomprising a shield can formed to have a through hole at a connectionunit of the third PCB and the wire spring and at a positioncorresponding to a lens module.
 5. The camera module as claimed in claim1, wherein the holder module comprises: an outer blade formed to havethe first coil wound on its outer circumferential face; a bobbinelastically supported by an elastic member on an upper side of the outerblade, disposed movably up and down within the outer blade, andconfigured to have a second coil wound on its outer circumferential faceand to have the at least one lens installed therein; and upper and lowerelastic members disposed on respective upper and lower sides of thebobbin and configured to elastically support the bobbin against theouter blade, wherein a space unit is formed at a center of the firstcoil so that magnetic force is applied toward the second coil.
 6. Thecamera module as claimed in claim 2, wherein a central part of the yoketoward the holder module is protruded.
 7. The camera module as claimedin claim 1, wherein the holder module comprises: an outer blade formedto have the first coil wound on its outer circumferential face; a bobbinelastically supported by an elastic member on an upper side of the outerblade, disposed movably up and down within the outer blade, andconfigured to have a second coil wound on its outer circumferential faceand to have the at least one lens installed therein; and upper and lowerelastic members disposed on respective upper and lower sides of thebobbin and configured to elastically support the bobbin against theouter blade.
 8. The camera module as claimed in claim 7, wherein thesecond PCB is installed at a bottom surface of the outer blade.
 9. Thecamera module as claimed in claim 8, wherein the second PCB is fixed tothe bottom surface of the outer blade by an adhesive member.
 10. Thecamera module as claimed in claim 1, wherein the wire springs are madeof metal material, and the wire springs conduct electricity to thesecond and the third PCBs.
 11. A camera module, comprising: a firstPrinted Circuit Board (PCB) configured to have an image sensor mountedthereon; a housing unit disposed over the first PCB; a holder modulespaced apart from a bottom surface within the housing unit at a specificinterval and configured to have a first coil wound on its outercircumferential face and to include at least one lens therein, a secondPCB combined with the bottom surface of the holder module; a third PCBdisposed over the holder module; and a plurality of wire springs eachconfigured to have one end connected to the second PCB and the other endconnected to the third PCB, wherein a number of the wire springs is atleast 6 so that a power source of two polarities for auto-focusingcontrol and a power source of four polarities for optical imagestabilizer are supplied to the holder module through connection betweenthe wire springs and the second and the third PCBs.
 12. The cameramodule as claimed in claim 7, wherein: the second coil is electricallyconnected to a lower spring, and the lower spring is electricallyconnected to the wire spring in the second PCB.
 13. The camera module asclaimed in claim 7, wherein the second coil is directly connected to thesecond PCB so that the second coil conducts electricity to the secondPCB.
 14. The camera module as claimed in claim 7, wherein a space unitis formed at a center of the first coil so that magnetic force isapplied toward the second coil.
 15. The camera module as claimed inclaim 1, further comprising a buffer member interposed between theholder module and the third PCB.
 16. The camera module as claimed inclaim 15, wherein the buffer member is disposed on an entire surfacefacing the third PCB on a top of the housing unit.
 17. The camera moduleas claimed in claim 15, wherein the buffer member is formed of animpact-resistant member made of microcellular polyurethane.
 18. Thecamera module as claimed in claim 15, wherein the third PCB includes apad having, at its center, a through hole through which the wire springpasses.
 19. The camera module as claimed in claim 18, wherein the buffermember is spaced apart from any one of an end of the through hole and anend of the pad at a specific interval.
 20. The camera module as claimedin claim 18, wherein the buffer member is disposed at an end of thethrough hole and at an end of the pad.
 21. The camera module as claimedin claim 1, wherein further comprising a buffer unit in some region ofeach of the wire springs.
 22. The camera module as claimed in claim 21,wherein each of the buffer units is formed near a connection unit of thewire spring and the third PCB.
 23. The camera module as claimed in claim21, wherein the buffer unit is formed both at a connection unit of thewire spring and the third PCB and near the connection unit of the wirespring and the second PCB.
 24. The camera module as claimed in claim 21,wherein the buffer unit is formed near the connection unit of the wirespring and the second PCB.
 25. The camera module as claimed in claim 1,further comprising an impact absorption unit formed in a sidewall of thehousing unit and elastically deformed when an impact is generated in thehousing unit.
 26. The camera module as claimed in claim 25, wherein thehousing unit comprises: a first housing disposed on an upper side of thefirst PCB; a second housing disposed on an upper side of the firsthousing and configured to have the third PCB disposed thereon; first andsecond permanent magnets interposed between the first and the secondhousings; and yokes each disposed between the first and the secondpermanent magnets and configured to transfer magnetic force to theholder module, wherein the impact absorption unit is formed in thesecond housing.
 27. The camera module as claimed in claim 26, whereinthe impact absorption unit is formed in a sidewall of the secondhousing.
 28. The camera module as claimed in claim 27, wherein theimpact absorption unit comprises one or more grooves formed in thesidewall of the second housing to a specific depth.
 29. The cameramodule as claimed in claim 28, wherein the groove has a depth smallerthan a thickness of the second housing.
 30. The camera module as claimedin claim 27, wherein: the impact absorption unit comprises three or moregrooves foamed in the entire sidewall of the second housing to aspecific depth, the grooves have an identical depth, and the grooves areformed in inside and outside of the second housing in such a way as tocross each other and are spaced apart from one another.
 31. A cameramodule, comprising: a first Printed Circuit Board (PCB) configured tohave an image sensor mounted thereon; a housing unit disposed over thefirst PCB; a holder module spaced apart from a bottom surface within thehousing unit at a specific interval and configured to have a first coilwound on its outer circumferential face and to include at least one lenstherein; a second PCB combined with the bottom surface of the holdermodule; a third PCB disposed over the holder module; a plurality of wiresprings each configured to have one end connected to the second PCB andthe other end connected to the third PCB; and buffer units eachintegrally formed with a wire spring at a position where the wire springis connected to the third PCB, wherein the buffer units are formed bybending the wire springs in a coil spring form.
 32. The camera module asclaimed in claim 11, wherein four pairs of the wire springs having anidentical length are disposed at respective corners of the holdermodule.
 33. A camera module, comprising: a position detection portionfor detecting a position of the camera module; a controller forgenerating a control signal if the position of the camera moduledetected by the position detection portion corresponds to a conditionthat the camera module drops; and a Optical Image Stabilization (OIS)driver for reducing internal structures of the camera module in responseto the control signal received from controller; a lens barrel includingat least one sheet of a lens; and a casing having the lens barrelembedded therein, wherein the OIS driver moves the lens barrel andcomprises a coil installed in the lens barrel and magnets installedwithin the casing, and wherein the lens barrel is suspended from thecasing through wire springs and connected to the coil, and the lensbarrel supplies current to the coil.
 34. The camera module as claimed inclaim 33, wherein the OIS driver is driven according to any one of alens barrel shift method and a camera module tilt method.
 35. The cameramodule as claimed in claim 33, further comprising: a camera unitconfigured to capture an image of a subject; and a casing configured tohave the camera unit embedded therein, wherein the OIS driver moves thecamera unit and comprises magnets installed in the camera unit and coilsinstalled within the casing.
 36. The camera module as claimed in claim33, further comprising a groove formed at a center of a bottom of thecamera unit in order to prevent a center of the camera unit from moving,wherein a pivot inserted into the groove is formed in the casing. 37.The camera module as claimed in claim 33, further comprising an elasticunit for restoring the camera module to an original position when anelectromagnetic action of the OIS driver disappears.
 38. The cameramodule as claimed in claim 30, wherein the position detection portioncomprises at least one of a gyro sensor, an acceleration sensor, and anangular velocity sensor.